MSD Pro-Billet advice please

General Chat About Electrics, And Ignition Systems.

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sidecar
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Re: MSD Pro-Billet advice please

Post by sidecar » Tue May 15, 2018 8:57 am

A clockwork watch has style, a cheap electronic one doesn't!

Also with a locked out dizzy and an ignition system that it triggered by the crank means that all that the dizzy is doing is distributing the HT to each plug, no great accuracy is required for that, the rotor just needs to be pointing at the HT post.

Having said all that then yes I agree that a knacker old Lucas dizzy with worn out bob weight springs is not going to be very good but that's not what's under discussion here.



DaveEFI
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Re: MSD Pro-Billet advice please

Post by DaveEFI » Tue May 15, 2018 12:05 pm

With an eight cylinder dizzy locked out, you have to be careful to prevent cross firing, as the rotor arm no longer tracks the spark timing. It can be better to keep the mechanical advance purely for the rotor arm position, if using a crank trigger and dizzy.

Rotor arms and caps tracking etc is also often a real problem with high energy sparks.

Of course if you simply like the look of a dizzy, that is your choice. :D
Dave
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sidecar
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Re: MSD Pro-Billet advice please

Post by sidecar » Tue May 15, 2018 2:10 pm

No issues with cross firing with the MSD setup. I spent along time checking this out, at high advance figures the front of the rotor arm lines up with each HT post and at low advance figures the trailing edge of the rotor arm lines up with the HT post so there is no way that it is going to cross fire to another cylinder. I also took into account that at low RPM there are 5 sparks across a 20 degree (at the crank, 10 at the dizzy) duration.

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